Because TikTok is owned by one of our adversaries. They’ve been accused of pushing propaganda and they just accidentally proved how effective they can be at causing political change in the US.

Exactly what their opponents were afraid they had the power to do.

It looks REALLY bad. In this case it wasn’t anything sinister and they were open about it but tactically it was probably a massive mistake.

Also why didn’t they just tell everyone in the US? Why did only certain users get the message? Because of where they lived? Because they were voting age? They also proved they have an ability to target specific people for political action based on some (unknown) criteria.

That also looks horrible and plays right into their opponents hands.